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<p>The QSignalMapper class bundles signals from identifiable senders. <a href="#details">More...</a></p>
<pre> #include &lt;QSignalMapper&gt;</pre><p>Inherits <a href="qobject.html">QObject</a>.</p>
<ul>
<li><a href="qsignalmapper-members.html">List of all members, including inherited members</a></li>
<li><a href="qsignalmapper-qt3.html">Qt 3 support members</a></li>
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<a name="public-functions"></a>
<h3>Public Functions</h3>
<ul>
<li><div class="fn"/><b><a href="qsignalmapper.html#QSignalMapper">QSignalMapper</a></b> ( QObject * <i>parent</i> = 0 )</li>
<li><div class="fn"/><b><a href="qsignalmapper.html#dtor.QSignalMapper">~QSignalMapper</a></b> ()</li>
<li><div class="fn"/>QObject * <b><a href="qsignalmapper.html#mapping">mapping</a></b> ( int <i>id</i> ) const</li>
<li><div class="fn"/>QObject * <b><a href="qsignalmapper.html#mapping-2">mapping</a></b> ( const QString &amp; <i>id</i> ) const</li>
<li><div class="fn"/>QObject * <b><a href="qsignalmapper.html#mapping-3">mapping</a></b> ( QWidget * <i>widget</i> ) const</li>
<li><div class="fn"/>QObject * <b><a href="qsignalmapper.html#mapping-4">mapping</a></b> ( QObject * <i>object</i> ) const</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#removeMappings">removeMappings</a></b> ( QObject * <i>sender</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#setMapping">setMapping</a></b> ( QObject * <i>sender</i>, int <i>id</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#setMapping-2">setMapping</a></b> ( QObject * <i>sender</i>, const QString &amp; <i>text</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#setMapping-3">setMapping</a></b> ( QObject * <i>sender</i>, QWidget * <i>widget</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#setMapping-4">setMapping</a></b> ( QObject * <i>sender</i>, QObject * <i>object</i> )</li>
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<ul>
<li><div class="fn"/>29 public functions inherited from <a href="qobject.html#public-functions">QObject</a></li>
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<a name="public-slots"></a>
<h3>Public Slots</h3>
<ul>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#map">map</a></b> ()</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#map-2">map</a></b> ( QObject * <i>sender</i> )</li>
</ul>
<ul>
<li><div class="fn"/>1 public slot inherited from <a href="qobject.html#public-slots">QObject</a></li>
</ul>
<a name="signals"></a>
<h3>Signals</h3>
<ul>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#mapped">mapped</a></b> ( int <i>i</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#mapped-2">mapped</a></b> ( const QString &amp; <i>text</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#mapped-3">mapped</a></b> ( QWidget * <i>widget</i> )</li>
<li><div class="fn"/>void <b><a href="qsignalmapper.html#mapped-4">mapped</a></b> ( QObject * <i>object</i> )</li>
</ul>
<ul>
<li><div class="fn"/>1 signal inherited from <a href="qobject.html#signals">QObject</a></li>
</ul>
<h3>Additional Inherited Members</h3>
<ul>
<li><div class="fn"/>1 property inherited from <a href="qobject.html#properties">QObject</a></li>
<li><div class="fn"/>5 static public members inherited from <a href="qobject.html#static-public-members">QObject</a></li>
<li><div class="fn"/>7 protected functions inherited from <a href="qobject.html#protected-functions">QObject</a></li>
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<a name="details"></a>
<hr />
<h2>Detailed Description</h2>
<p>The QSignalMapper class bundles signals from identifiable senders.</p>
<p>This class collects a set of parameterless signals, and re-emits them with integer, string or widget parameters corresponding to the object that sent the signal.</p>
<p>The class supports the mapping of particular strings or integers with particular objects using <a href="qsignalmapper.html#setMapping">setMapping</a>(). The objects' signals can then be connected to the <a href="qsignalmapper.html#map">map</a>() slot which will emit the <a href="qsignalmapper.html#mapped">mapped</a>() signal with the string or integer associated with the original signalling object. Mappings can be removed later using <a href="qsignalmapper.html#removeMappings">removeMappings</a>().</p>
<p>Example: Suppose we want to create a custom widget that contains a group of buttons (like a tool palette). One approach is to connect each button's <tt>clicked()</tt> signal to its own custom slot; but in this example we want to connect all the buttons to a single slot and parameterize the slot by the button that was clicked.</p>
<p>Here's the definition of a simple custom widget that has a single signal, <tt>clicked()</tt>, which is emitted with the text of the button that was clicked:</p>
<pre> class ButtonWidget : public QWidget
 {
     Q_OBJECT

 public:
     ButtonWidget(QStringList texts, QWidget *parent = 0);

 signals:
     void clicked(const QString &amp;text);

 private:
     QSignalMapper *signalMapper;
 };</pre>
<p>The only function that we need to implement is the constructor:</p>
<pre> ButtonWidget::ButtonWidget(QStringList texts, QWidget *parent)
     : QWidget(parent)
 {
     signalMapper = new QSignalMapper(this);

     QGridLayout *gridLayout = new QGridLayout;
     for (int i = 0; i &lt; texts.size(); ++i) {
         QPushButton *button = new QPushButton(texts[i]);
         connect(button, SIGNAL(clicked()), signalMapper, SLOT(map()));
         signalMapper-&gt;setMapping(button, texts[i]);
         gridLayout-&gt;addWidget(button, i / 3, i % 3);
     }

     connect(signalMapper, SIGNAL(mapped(const QString &amp;)),
             this, SIGNAL(clicked(const QString &amp;)));

     setLayout(gridLayout);
 }</pre>
<p>A list of texts is passed to the constructor. A signal mapper is constructed and for each text in the list a <a href="qpushbutton.html">QPushButton</a> is created. We connect each button's <tt>clicked()</tt> signal to the signal mapper's <a href="qsignalmapper.html#map">map</a>() slot, and create a mapping in the signal mapper from each button to the button's text. Finally we connect the signal mapper's <a href="qsignalmapper.html#mapped">mapped</a>() signal to the custom widget's <tt>clicked()</tt> signal. When the user clicks a button, the custom widget will emit a single <tt>clicked()</tt> signal whose argument is the text of the button the user clicked.</p>
<p>See also <a href="qobject.html">QObject</a>, <a href="qbuttongroup.html">QButtonGroup</a>, and <a href="qactiongroup.html">QActionGroup</a>.</p>
<hr />
<h2>Member Function Documentation</h2>
<h3 class="fn"><a name="QSignalMapper"></a>QSignalMapper::QSignalMapper ( <a href="qobject.html">QObject</a> * <i>parent</i> = 0 )</h3>
<p>Constructs a <a href="qsignalmapper.html">QSignalMapper</a> with parent <i>parent</i>.</p>
<h3 class="fn"><a name="dtor.QSignalMapper"></a>QSignalMapper::~QSignalMapper ()</h3>
<p>Destroys the <a href="qsignalmapper.html">QSignalMapper</a>.</p>
<h3 class="fn"><a name="map"></a>void QSignalMapper::map ()&nbsp;&nbsp;<tt> [slot]</tt></h3>
<p>This slot emits signals based on which object sends signals to it.</p>
<h3 class="fn"><a name="map-2"></a>void QSignalMapper::map ( <a href="qobject.html">QObject</a> * <i>sender</i> )&nbsp;&nbsp;<tt> [slot]</tt></h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>This slot emits signals based on the <i>sender</i> object.</p>
<h3 class="fn"><a name="mapped"></a>void QSignalMapper::mapped ( int <i>i</i> )&nbsp;&nbsp;<tt> [signal]</tt></h3>
<p>This signal is emitted when <a href="qsignalmapper.html#map">map</a>() is signalled from an object that has an integer mapping set. The object's mapped integer is passed in <i>i</i>.</p>
<p>See also <a href="qsignalmapper.html#setMapping">setMapping</a>().</p>
<h3 class="fn"><a name="mapped-2"></a>void QSignalMapper::mapped ( const <a href="qstring.html">QString</a> &amp; <i>text</i> )&nbsp;&nbsp;<tt> [signal]</tt></h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>This signal is emitted when <a href="qsignalmapper.html#map">map</a>() is signalled from an object that has a string mapping set. The object's mapped string is passed in <i>text</i>.</p>
<p>See also <a href="qsignalmapper.html#setMapping">setMapping</a>().</p>
<h3 class="fn"><a name="mapped-3"></a>void QSignalMapper::mapped ( <a href="qwidget.html">QWidget</a> * <i>widget</i> )&nbsp;&nbsp;<tt> [signal]</tt></h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>This signal is emitted when <a href="qsignalmapper.html#map">map</a>() is signalled from an object that has a widget mapping set. The object's mapped widget is passed in <i>widget</i>.</p>
<p>See also <a href="qsignalmapper.html#setMapping">setMapping</a>().</p>
<h3 class="fn"><a name="mapped-4"></a>void QSignalMapper::mapped ( <a href="qobject.html">QObject</a> * <i>object</i> )&nbsp;&nbsp;<tt> [signal]</tt></h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>This signal is emitted when <a href="qsignalmapper.html#map">map</a>() is signalled from an object that has an object mapping set. The object provided by the map is passed in <i>object</i>.</p>
<p>See also <a href="qsignalmapper.html#setMapping">setMapping</a>().</p>
<h3 class="fn"><a name="mapping"></a><a href="qobject.html">QObject</a> * QSignalMapper::mapping ( int <i>id</i> ) const</h3>
<p>Returns the sender <a href="qobject.html">QObject</a> that is associated with the given <i>id</i>.</p>
<p>See also <a href="qsignalmapper.html#setMapping">setMapping</a>().</p>
<h3 class="fn"><a name="mapping-2"></a><a href="qobject.html">QObject</a> * QSignalMapper::mapping ( const <a href="qstring.html">QString</a> &amp; <i>id</i> ) const</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<h3 class="fn"><a name="mapping-3"></a><a href="qobject.html">QObject</a> * QSignalMapper::mapping ( <a href="qwidget.html">QWidget</a> * <i>widget</i> ) const</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>Returns the sender <a href="qobject.html">QObject</a> that is associated with the given <i>widget</i>.</p>
<h3 class="fn"><a name="mapping-4"></a><a href="qobject.html">QObject</a> * QSignalMapper::mapping ( <a href="qobject.html">QObject</a> * <i>object</i> ) const</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>Returns the sender <a href="qobject.html">QObject</a> that is associated with the given <i>object</i>.</p>
<h3 class="fn"><a name="removeMappings"></a>void QSignalMapper::removeMappings ( <a href="qobject.html">QObject</a> * <i>sender</i> )</h3>
<p>Removes all mappings for <i>sender</i>.</p>
<p>This is done automatically when mapped objects are destroyed.</p>
<h3 class="fn"><a name="setMapping"></a>void QSignalMapper::setMapping ( <a href="qobject.html">QObject</a> * <i>sender</i>, int <i>id</i> )</h3>
<p>Adds a mapping so that when <a href="qsignalmapper.html#map">map</a>() is signalled from the given <i>sender</i>, the signal mapped(<i>id</i>) is emitted.</p>
<p>There may be at most one integer ID for each sender.</p>
<p>See also <a href="qsignalmapper.html#mapping">mapping</a>().</p>
<h3 class="fn"><a name="setMapping-2"></a>void QSignalMapper::setMapping ( <a href="qobject.html">QObject</a> * <i>sender</i>, const <a href="qstring.html">QString</a> &amp; <i>text</i> )</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>Adds a mapping so that when <a href="qsignalmapper.html#map">map</a>() is signalled from the given <i>sender</i>, the signal mapped(<i>text</i> ) is emitted.</p>
<p>There may be at most one text for each sender.</p>
<h3 class="fn"><a name="setMapping-3"></a>void QSignalMapper::setMapping ( <a href="qobject.html">QObject</a> * <i>sender</i>, <a href="qwidget.html">QWidget</a> * <i>widget</i> )</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>Adds a mapping so that when <a href="qsignalmapper.html#map">map</a>() is signalled from the given <i>sender</i>, the signal mapped(<i>widget</i> ) is emitted.</p>
<p>There may be at most one widget for each sender.</p>
<h3 class="fn"><a name="setMapping-4"></a>void QSignalMapper::setMapping ( <a href="qobject.html">QObject</a> * <i>sender</i>, <a href="qobject.html">QObject</a> * <i>object</i> )</h3>
<p>This is an overloaded member function, provided for convenience.</p>
<p>Adds a mapping so that when <a href="qsignalmapper.html#map">map</a>() is signalled from the given <i>sender</i>, the signal mapped(<i>object</i> ) is emitted.</p>
<p>There may be at most one object for each sender.</p>
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